Seems like you've covered the most obvious cause of ignition problems. How hard is it to cock the hammer? Is it really easy to cock or does it take a bit of force to get it all the way to full cock? CCI makes their caps a bit thicker then Remington and it takes a good strike to set them off. If the hammer draw seems a bit light, try tightening the tension on the mainspring in the grip...there should be a screw that puts more tension on the spring. After you've ramped that up a bit, try a few shots and see if you still have the problem.